This invention is in the field of security and access control, and the invention particularly concerns access to coin box locks and other situations wherein a single mechanical key fits a number of locks and wherein there is a need to control the instances of opening each lock and to maintain a record thereof.
In the past, a number of electronic security features have been added to mechanical locks which use mechanical types of cylinders. In addition, locking elements controlled by electronic means have been disclosed in combination with non-mechanical types of tumblers, such as in Clarkson et al. U.S. Pat. No. 4,712,398. Some of the existing electronic systems have employed keypads, some have employed cards, some have had purely electronic, magnetic or optical access control devices, and some have employed mechanical keys equipped with electronic circuitry.
With respect to the present invention, distinction is made among purely electronic, magnetic or optical keys; mechanical keys equipped with electronic, magnetic or optical features; and mechanical keys which operate solely by mechanical bittings, whether those bittings be pin tumbler, dimples or other mechanical patterns.
A key comprised of purely electronic circuitry, magnetic or optical data storage for determining and granting access is an electronic key. In the use of such a key, the circuitry or recorded data is transferred to a reader associated with a lock, and the reader recognizes a pattern or code held by the key. The key does not carry any mechanical cut or bitting configuration needed for granting access. Keys of this type can be found in U.S. Pat. Nos. 3,797,936 (Dimitriadis), 4,209,782 (Donath et al.), 4,257,030 (Bruhin et al.), 4,620,088 (Flies), 4,659,915 (Flies) and 4,789,859 (Clarkson et al.).
Keys referred to as mechanical keys are those which activate a mechanical device, with a pattern of mechanical bittings, by direct contact with the interpreting device, i.e. the tumblers or other pattern-holding apparatus contained in the lock. In a typical pin tumbler lock, access is granted based on the depth and configuration of key cuts meeting the tumblers. In most cases, once proper alignment is established in the tumblers, the keyholder is able to turn the key to lock and unlock the locking device. However, in some cases of mechanical keys, a push or pull action may be necessary for locking and unlocking of the device. The tumblers mentioned above can be pin tumblers, lever tumblers, disk.tumblers, rotary disk tumblers, slider tumblers, or combinations of several of these incorporated within the same lock. Examples of purely mechanical keys are found in U.S. Pat. Nos. 480,299 (Voight), 550,111 (Sargent), 564,029 (Sargent), 3,208,248 (Tornoe), 4,723,427 (Oliver), 4,732,022 (Oliver) and 4,823,575 (Florian et al.).
Examples of mechanical keys equipped with electronic circuitry, magnetic or optical data storage or optical recognizable features can be found in U.S. Pat. Nos. 3,733,862 (Killmeyer), 4,144,523 (Kaplit), 4,326,124 (Faude), 4,562,712 (Wolter), 4,663,952 (Gelhard), 4,686,358 (Seckinger et al.), 5,245,329 (Gokcebay) and 5,140,317 (Hyatt, Jr. et al.). Such keys carry the secondary element, whether it comprises electronic circuitry or some other type of coded data or recognizable pattern, in addition to the key""s mechanically operating pattern or bitting. In some instances both mechanical and non-mechanical features of a key are used simultaneously.
U.S. Pat. No. 5,140,317, referenced above, discloses a combined mechanical lock/key combination which further includes an electronic feature for permitting opening of each lock in a system of similarly-keyed locks, only when authorized, and with a recording of each lock opening made. The system disclosed in the patent includes a mechanical key with a key cut configuration, and with means for making electrical contact with electronics inside the lock. A separate box is connected by electric wiring to the key, the box including a keypad, a microprocessor, a battery for powering the system and a memory with stored data. The lock includes a retractable blocking means which blocks opening of the lock""s bolt, separately from the mechanical bitting, except when prescribed conditions are met. When a solenoid in the lock is activated the blocking means is retracted. The lock also includes its own microprocessor, which controls switching of power to the solenoid, and with a memory within the lock storing data. The microprocessor within the lock compares coded data read from the key with coded data in the memory within the lock, and thus controls powering of the solenoid to situations in which a comparison, made within the lock""s microprocessor, determines that coded data read from the key matches coded data in the lock""s memory. Also, the lock""s microprocessor further calculates a new code for the lock, after each opening of the lock.
The above patent is applicable to coin locks and other situations wherein a mehanic al key has bit ting matched to a large number of similar locksi but where control of the opening of each lock is desired, and where a record is needed of each lock""s opening. The system has been applied to pay telephone coin boxes. However, besides requiring the inclusion of a microprocessor and associated memory within the lock itself, the system of the patent requires additional hardware within the lock casing or the coin box for blocking the op ening of the lock except when the microprocessor determines it is proper. The disclosed system thus is a pplicable only to locks wherein considerable space is available for these added elements, and would be difficult or impossible to implement-in situations with little space available. In addition, considerable modification in retrofitting of existing locks is required, increasing cost of implementing the system, in addition to high cost of manufacture and materials.
In the case of coin collection from parking meters, counters have been included in certain electronic parking meters to count the total money which has been inserted into the meter. These electronic meters have a built in interface to communicate the data via infrared transmission to a portable data collection unit under the control of an auditor. Each time a coin collection operator collects coins from the parking meters, the counter in each meter automatically resets to zero. The auditing function is separate; auditors are supposed to use the separate data collection units to audit the total of money being collected from each meter, along with several other statistics. However, in such a system there is no way to pinpoint a skimming of coins or to identify the responsible personnel when coins have been skimmed. The meter-by-meter audit is conducted at a different time from the collection of coins.
It is an object of the invention described below to provide a system which is very easily retrofitted into lock systems having a single key operating a number of locks, and which avoids the need for electronics, solenoids or other hardware which would take up space within the coin box or the lock casing adjacent to the lock. In additional aspects of the invention, it is an object to provide a convenient means for electronically transferring a total of coins collected from each coin lock box. (such as in parking meters) to a storage device carried by the operator, preferably within the key unit, to prevent collection of the coins until such data has been transferred, and, in another embodiment, to record each instance of access to a lock, by key number, in the situation of a lock accessible by a number of different keys.
In accordance with the present invention, a key and lock combination achieves the objectives of security in a coin lock type system wherein a single mechanical key is fitted to a plurality of similarly keyed mechanical lock cylinders. The system of the invention includes a key which is self-contained, with a key head having a microprocessor, memory and battery, as well as a contact point for a one wire bus connection with the lock. In certain embodiments the lock is fitted with a special EEPROM which records each instance of the lock""s being accessed, e.g. by time, date and key number, for the situation where a single lock can be accessed by a number of keys.
The lock, which may be a coin collection lock for telephones, parking meters, slot machines or other similar applications, has an electronic access feature which occupies no more space than the mechanical lock itself. Nothing is required outside the lock cylinder, and in fact, in preferred embodiments, all electronics and hardware are contained in the cylinder plug, aside from a small recess or bore which is provided in the cylinder shell.
In a specific embodiment the cylinder plug, in a typical rotatable plug type lock cylinder, contains a one-wire bus connection for contact with the key, a blocking pin which prevents rotation of the plug independently of the mechanical bittings (shear plane tumblers), and an addressable switch for supplying power to the solenoid to release the blocking pin only upon specified conditions being met. A decision as to whether the addressable switch should conduct power to the solenoid is made inside the key, not the lock. Within the key""s database is a list of locks, by serial number or code, which are within the system and are normally openable by the mechanical key. Since the locks in a route collection system may only be permitted to be accessed at certain times (the microprocessor preferably includes a clock/calendar) and not more than once by a keyholder on a route, the microprocessor can grant or deny access on these bases. Further, within the database in a preferred embodiment is a list or table associating a secure addressing code for the particular addressable switch with each serial number or coded ID number of a lock. When a lock is xe2x80x9creadxe2x80x9d by the key, the key""s microprocessor determines whether it is appropriate for the lock to be opened at that time, and if so, it sends the approval code back into the lock to effect switching of the addressable switch. This conducts power to the solenoid, releasing the blocking pin.
The one wire bus connection in the cylinder plug may be generally as disclosed in the above-referenced U.S. Pat. No. 5,367,295, and may have a spring-biased, isolated contact which extends forward from a bore in the cylinder plug; alternatively, the isolated contact may be flush with the plug or recessed, so long as the key""s contract reaches the lock""s contact. The metal of the cylinder plug of course forms a ground connection.
In a preferred embodiment the electronics included on the cylinder plug comprise a xe2x80x9cSilicon Serial Numberxe2x80x9d as manufactured by Dallas Semiconductor, as an ID for the lock. Such an electronic ID device has a coded serial number which is readable by application of a voltage. The Silicon Serial Number may be a laser-etched 64-bit ROM with a 48-bit serial number, powered by the data line with no need for an additional power source. The ID chip requires no standby power to maintain the memory of the serial number. The device is quite small, only about 3.7 mm by 4 mm by 1.5 mm, ideally suited for purposes of the present invention. A second electronic device, connected to the ID device, is the addressable switch. This electronic component, also manufactured by Dallas Semiconductor, is approximately the same size as the ID device. The addressable switch has its own code, and will switch the circuit to conduct power to the solenoid only when it is addressed with the proper code. This particular addressable switch is of a type that resets with a second application of the switch code, which is automatically issued by the microprocessor after a prescribed time delay to allow opening of the lock, e.g. one to three seconds. Means are provided in the circuit, preferably between the addressable switch and the ID device, for preventing reading of the code of the addressable switch from outside the lock. Thus, the key first reads the ID code, identifying the lock which is to be opened, and if opening is authorized, the key sends back the code for the addressable switch, upon which the addressable switch switches the circuit to conduct power from the key through to the solenoid to release the blocking pin. In a preferred embodiment, the opening of each lock is recorded by the microprocessor, in the data storage of the key. Each lock ID in the-database is marked as having been opened when that event has occurred, and preferably the time and date are-also marked.
The head of the key includes a data port for unloading data from the microprocessor and database, as to locks that were opened on the operator""s route and any other pertinent information regarding attempted lock openings, wrong PIN numbers, etc. Also, the key head preferably includes a recharging port for enabling the recharging of a battery within the key head.
Another feature of the invention is a small keypad on the head of the key. This can be used for additional security, to require an operator to input an authenticating code known only to the proper operator. Thus, the key cannot be used by an unauthorized person. The programming of the microprocessor preferably is set so that the operator enters his PIN number at the start of a route wherein a series of locks will be opened. The system can require an updated reentry of the PIN number at various intervals, if desired. Further, if the lock ID read by the key from a lock does not exist in the key""s database, the key, which includes a small display, can request the operator to reenter his PIN number. Further use of the key can be denied the operator if the newly entered PIN number is not the correct number, or if several locks not existing in the key""s database (or not authorized to be opened at the particular time) are attempted.
In one preferred embodiment, the key has a key blade, containing the mechanical bittings, which is removable from the key head. This enables the electronics of a key, or the mechanical bitting of a key, to be changed without producing an entirely new key. Locks may be changed in the manner of typical mechanical locks, by replacing the cylinder, or refitting the mechanical bitting (new sets of tumblers), and changing the cylinder plug.
In another aspect of the invention, locks associated with coin collection routes are provided with counter devices for counting the amount of money stored in the coin box, with provision for electronically interfacing with a portable data collection unit for recording the total money which will be removed from the coin box. This is particularly useful in coin collection situations such as parking meters, which prior to this invention have already been provided with such electronic counters and interfacing units utilizing infrared data transmission. With the invention described herein the system does not allow a parking meter (or other coin box) to be accessed by the collection operator until the data showing the total money in the box have been transferred to the portable data collection unit. Also in accordance with this invention, the portable data collection unit preferably is integral with the key device used by the coin collection operator. This not only provides for a single device to be used by the operator for data collection and for actual opening of the coin box; it also enables the intelligent key, with a microprocessor and memory as described above, to prevent the opening of the coin box until such data have been collected. In this way the operator cannot remove coins without providing an automatic audit of the amount of money to be removed from each parking meter or other coin box.
An additional feature in a preferred embodiment of the invention provides for the ability to record audit trail data from the coin collection route. This feature enables management to recreate collection data in the case of loss (or alleged loss) of a key. In the event the coin collector claims he has lost the key at the end of the day, and that the money he delivers is the total of what has been collected that day (while retaining some of the money for the collector""s drug habit, for example), management can return to the parking meters (or other devices) on the collector""s route and recreate the coin collection data by going through the same route, meter by meter. For this purpose the parking meter is provided with a memory which retains the data representing total stored money after the coin collection operator has transferred the data to the key device. One preferred way of implementing this storage is to transfer the total stored money data from the key""s memory into a special EEPROM in the lock since the coin counter is separate and independent and not connected to the lock electronics. This can be done by first reading the money data using the key device, which transfers the data into the key, while the counter may then automatically reset to zero; then, when the user inserts the key into the lock, automatically transferring the stored money data into the lock itself, to be retained on the EEPROM of the lock until such time as (1) the route collector returns again to collect more coins; or (2) an auditor goes out to check each parking meter by inserting a specially programmed key device into each meter, for the sole purpose of transferring the electronically stored total money data into the key device. In either event, the stored data in the special EEPROM can be deleted.
In another aspect of the invention, the lock and key apparatus are used in a situation where a single lock securing stored money is accessible by a plurality of keys held by different personnel. A prime example is a slot machine. In an embodiment of the invention directed at this purpose, the lock has the ability to record entry data sent by the key device, that is, time and date of each entry and by key number. This feature will enable downloading of an audit trail revealing which personnel have opened the particular lock and at which times. If coin counting is a part of the particular device, the information as to total money stored or received as of the time of each lock accessing can also be retained for the audit. As in the embodiments described above, the special rewritable EEPROM for this purpose may be compactly contained on the cylinder plug of the locks, without requiring space-consuming retrofitted apparatus.
It is thus seen that the mechanical/electronic lock and key of the invention provides, in an extremely compact fashion, electronic access control to a conventional mechanical lock. No additional space in a lock is required to implement the system of the invention. The system is particularly useful where a single key is matched to a number of locks, and a key of the invention has onboard microprocessor, database and battery so that all comparison and decision making as to access is performed in the key itself, without requiring any microprocessor or data storage within the lock. Only a xe2x80x9cslavexe2x80x9d unit is included in the cylinder, responding to what the xe2x80x9cmasterxe2x80x9d (the key) sends. There are not intelligence capabilities in the lock itself. The system can provide audit capability for coin collection routes; other embodiments provide audit capability where a single lock (as in a slot machine can be accessed by multiple keys. These and other objects, advantages and features of the invention will be apparent from the following description of a preferred embodiment, considered along with the accompanying drawings.